It is well known that the PBH could be produced via gravitational collapses of the enhanced primordial curvature perturbations on small scales [1]}.
The mass function of PBH is determined by the power spectrum of primordial curvature perturbations (see e.g. Ref. [2]}).
To produce a sizable quantity of PBH, the scalar spectral amplitude should conquer a critical magnitude \(\sim 0.1\)  [3]}, which is about eight orders of magnitudes larger than the spectral amplitude on large scales.
On the other hand, the dynamics of cosmic inflation [4]}, [5]}, [6]} is one of the greatest puzzles of cosmology to be uncovered.
In particular, the small-scale primordial curvature perturbations were generated by quantum fluctuations at the late-time stage of inflation.
Their power spectrum encodes characteristic information of the late-time dynamics of inflation, which could be different from that of the early-time one measured precisely with experiments of CMB [7]}, [8]} and LSS [9]}, [10]}.
Therefore, we can gain more information of cosmic inflation via investigating the PBH.
